Drawing-board.



PATENTE) Nov. .5', 1907. H. L. BURBANK & J. W. MANsoN.

DRAWING BOARD.

APPuoA'rloN FILED APn.e.19o7.

INVENToRs WI TNESSE S 1HE Nalmls Fzrxles cn.. wAsHlNaraN, n. c.

' No. 870,224. PATENTE)` NOV'. 5, 1907.

H. L. BURBANK & J. W. MANSON.

2 SHEETS-SHEET 2 lV l a Elyl JNz/ENToRi Eig.

DRAWING BOARD. APPLIOATION FILED APB e 1907 WYTNESSES:

UNITE STATES vPATENT OFFICE.

HENRY L. BURBANK AND JAMES W. MANSON, OF AKRON, OHIO.

DRAWING-BOARD.

Specification of Letters Patent.

Patented Nov. 5, 1907.

Application tiled April 6, 1907. Serial No. 366,866.

To all whom it may concern:

Be it known that we, HENRY L. BURBANK and JAMES W. MANsoN, citizens of the United States, residing at Akron, in the county of Summit and State of Ohio, have invented a new and useful Drawing-Board, of which the following is a specification.

Our invention relates to improvements in rotary drawing boards, and particularly to the rotary drawing board described in Patent 836,919, granted to us on November 27th, 1906. i

The objects of our invention are to provide improved means for rotating the board proper, and stopping it at any desired angle for adjusting the tension of the wire controlling the straight edge; and for obtaining successive parallel movements of the straight edge. We attain these objects bythe mechanism illustrated in the accompanying drawings, in which Figure 1 is a plan view of the assembled drawing board; Fig. 2 is a section of Fig. 1 on the line :c x; Fig. 3 is a plan View of the upper bearing member; Fig. 4 is a section of Fig. 3 on the line y y; Fig. 5 is a plan vie'w of the lower bearing member; Fig. 6 4is a section of Fig. 5 on the line z z; Fig. 7 is a plan view of the protractor limb; Fig. 8 is a section of Fig. 7 on the line o o; Fig. 9 is a plan view of the straight edge wire tension adjusting device; Fig. 10 is a section of Fig. 9 on the line p p; Fig. 11 is a plan view of the adjustable spacing device; Fig. 12 is a section of part of Fig. 11 on the line q q, showing the arrangement of the drum, the pawl-arm and the notched spacing wheel; and Fig. 13 is an enlarged view of the pivoted extremities of the spacing and releasing pawls in Fig. 11, showing their relative positions when the spacing pawl is released.

In the following description like numerals refer to like parts, and the operator is supposed to be on the side of the board on which the beam 7 is shown, the motions of the straight edge toward and away from the operator being called the forward and backward movements respectively.

Referring more in detail to the drawings, in Fig. 1 the cross beams 2 and 3, the side beams 4 and 5, and the front beam 7 constitute the supporting frame. Flat pieces 23 and 24 are set into the frame as shown, their function being to support various parts of the mechanism hereinafter to be described. The bearing member 26, shown in plan and section in Figs. 5 and 6, is mounted on the cross beams 2 and 3 substantially at the center of the supporting fra-me, and has an upwardly projecting central portion 49 forming a socket in which the downwardly projecting pivot of the upper bearing member rotates. The upper bearing member 25 is shown in plan and section in Figs. 3 and 4. The board 1, Figs. l and 2,v is mounted on the upper bearing member 25 and rotates with it. The protractor limb 16, shown in plan and section in Figs. 7

and 8, is rotatably mounted on the upwardly projecting central portion 49 of the lower bearing member 26, and carries the pin 30 on which the pawl 27 is pivoted. The pawl 27, under pressure of the spring 29, engages interchangeably with the notches 51 in the periphery of the upper bearing member 25 when the board 1 and the upper bearing member 25 are rotated by the oper-- ator.

When it is desired to positively prevent the board from rotating and causing the spring actuated pawl 27 to ride out of the notch in which it has fallen, the cam 32 is forced against the end of the slidably mounted locking bar 31, the other end of which is pivotally attached to the pawl. The protractor limb 16 extends beyond the board 1 to the graduated arc 21, attached to the supporting frame, and near its extremity carries a clamp 33 adjustable by means of the screw and thumb nut 34. The indicator 28, mounted on the protractor limb, furnishes means to determine the degreeof angularity at which the limb is set. The straight edge 6 is held in parallelism by the Wire 22, which passes over the sheaves 8, 9, 10, 11, 12, 13, 14 and the drum 15. Beginning at the drum 15 the controlling wire 22 passes around sheave 13, to the under side of and over the sheave 9, thence to the upper side of and under the sheave 8, thence around the sheave 12 to and around the sheave 14, thence to the under side of and over the sheave 11, thence to the upper side of and under the sheave 10, thence to the drum 15, to which it may be attached, and round which it makes several turns. So far as controlling the parallelism of the straight edge is conce1-ned the drum l5 is essentially the equivalent of a sheave, and could, if necessary, be used in the place oi any one of the other sheaves before mentioned. The special function of the drum 15 will be described hereinafter. The straight edge 6 is attached near its ends to the wire 22 at two points, one of these being on the span of wire between the sheaves 8 and 9, the other point being on the span between the sheaves 10 and 11. The tension of the Wire is adjusted by moving the sheaves 12 and 13 toward or away from each other. To accomplish this the axles ofthe sheaves 12 and 13 are set in blocks sliding in the slotted frame 17, Figs. 9 and 10, and the blocks are drawn to or pushed away from each other by the right and left threaded screw 18, operated by the thumb wheel 19.

The drum 15, Figs. 11 and 12, is mounted on the pin 37 and carries the notched Wheel 35. The nut 36 serves to bind the notched wheel in position on the drum, and permits of the substitution of wheels having greater or less numbers of notches. The arm 38 is arotatable on the hub of the drum l5, but is held fast by the screw 2() and adjusting nuts 44. The spacing pawl 39 and the releasing pawl 4() are pivoted on pins fastened to the arm 38. In Fig. 13 the pivoted ends CII of the spacing and releasing pawls 39 and 40 are shown l on an enlarged scale, and the pivot pinsare represented by the numerals 45 and 46. lt will be noticed by reference to Fig. 13 that the pawls are slotted, each in the direction of its length, which permits them to slide as well as pivot on the pins.

The object of pivotally and slidably mounting the spacing and'rcleasing pawls will be understood by the following description of the operation of the spacing device. Pulling the straight edge toward the operator causes the wire 22 to turn the drum 15, and colisequently the notched wheel 35, against the pallet of the spacing pawl 39. As the spring 41 normally brings the pallets of the spacing and releasing pawls in engagement with the teeth of the wheel 35 the rotation of the wheel is stopped when the spacing pawl reaches the end of its sliding travel on the pin 45. The forward movement of the straight edge is therefore limited by the extent of the sliding movement of the spacing pawl. When the forward movement of the straight edge is arrested, the operator pushes the straight edge backward, and the releasing pawl 4() is forced against the body of the spacing pawl, thereby lifting the pallet of the spacing pawl out of the notched Wheel. The backward motion of the straight edge stops when the limit of sliding movement of the releasing pawl 40 on the pin 46 is reached. When the spacing pawl is forced forward by the spring 40 the gap-48 in the spacing pawl 39 is brought over the projecting portion 47 of the releasing pawl 40, and the lifting action of the pawl-4Q is removed. The pallet of the spacing pawl 39 is then free to drop into another notch of the wheel 35, in readiness for the next forward movement of the straight edge. 1n Fig. l1 the pawls are shown in the position they occupy when the forward motion of the straight edge is arrested, and in Fig. 13 they are shown in the positions they occupy immediately after the spacing pawl is released by the backward motion of the straight edge. The sliding movement of the spacing pawl being greater than that of the releasing pawl7 alternate forward and backward movements of the straight edge result in the straight edge approaching the operator by successive steps, the extent of which is determined by the pitch of the notched wheel. When it is desired to disengage the spacing and releasing pawls from the wheel 35 for the purpose of permitting' the straight edge to run free, the wedge 42 is pressed between the pawls by turning the lever 43 to the position indicated by the broken lines in Fig. 11. The wedge 42 is normally held away from contact with the pawls by a spring Having described our preferable arrangement, what we claim as our invention is:

1. In a drawing board, the sheaves 8, 9, 10, 11, 12, 13 and 14, and the drum 15, all mounted on the supporting frame of the said board, the said drum being interchangeable in respect of position with the sheaves 12, 13, or 14, means for increasing or decreasing the distance between the sheaves 12 and 13, in combination with the movable straight-edge G and the controlling wire 22, substantially as set forth and described.

2. In a drawing board, a rotating board, a supporting frame, a protractor limb rotatably mounted on an axis' coincident with the axis of rotation of the said rotating board, the said protractor limb extending beyond the said rotating board, a graduated scale attached to the said supporting frame, means for fastening the said protractor limb to the said supporting frame at various angles, and a pawl mounted on the said protractor limb, the said pawl interchangeably engaging with stops rotating with the said rotating, board, in combination, substantially as set forth and described 3, In a drawing board, a rotating board, a supporting frame, a protractor limb rotatably mounted on an axis coincident with the axis of rotation of the said rotating board, the said protractor limb extending beyond the said rotating board, a graduated scale attached to the said supporting frame, means for fastening the said protractor limb to the said supporting frame at various angles, and a pawl mounted on the said preti-actor limb, the said pawl interchangeably engaging with stops rotating with the said rotating board, a locking bar slidably mounted on the said protractor limb and pivotally attached at one end to the said pawl, and means mounted on the said protractor limb to prevent longitudinal movement of the said locking bar when desired, in combination, substantially as set forth and described.

4. In a drawing board, in combination, a straight-edge, a straight-edge controlling wire, a spacing device consisting of a drum around which the said controlling wire is coiled, a notched wheel rotating with the said drum, a spacing pawl and a releasing pawl both of which are pivotally and slidably mounted near the periphery of the said notched wheel, the said spacing pawl acting to limit the rotation of the said notched wheel in one direction, the said releasing pawl acting to limit the rotation of the said notched wheel in the contrary direction and to di'sengage the said spacing pawl from thesaid notched wheel when the said releasing pawl is slidably actuated by the rotation of the' said notched wheel, and means to restore the said spacing and releasing pawls to the respective positions in which they are ready to perform their function of limiting the rotation of the said notched wheel, substantially as set forth and described.

5. In a drawing board, in combination, a straight-edge, a straight-edge controlling wire, a spacing device consisting of a drum around which the said controlling wire is coiled, a notched wheel rotating with the said drum, a movable arm rotatable about the axis of the said drum, means for fasteningand adjusting the said arm, a spacing pawl and a releasing pawl, both of which are pivotally and slidably mounted on the said arm, the said spacing pawl acting to limit the rotation of the said notched wheel `in one direction, the said releasing pawl acting to limit the rotation of the said notched wheel in the contrary direction and to disengage the said spacing pawl from the said notched wheel when the said releasing pawl is slidably actuated by the rotation of the said notched wheel, and means to restore the said 'spacing and releasing pawls to the respective positions in which they are ready to perform their function of limiting the rotation ofthe said notched wheel, substantially as set forth and described.

6. In a drawing board, in combination, a straight-edge, a straight-edge controlling wire, a spacing device consisting of a drum around which the said controlling wire is coiled, a notched Wheel rotating with the said drum, a spacing pawl and a releasing pawl both of which are pivotally and slidably mounted near the periphery of the said notched Wheel, the said spacing pawl acting to limit the rotation of the said notched wheel in one direction, the said releasing pawl acting to limit the rotation of the said notched Wheel in the contrary direction and to disengage the said spacing pawl from the said notched wheel when the said releasing pawl is slidably actuated by the rotation of the said notched wheel, means to restore the said spacing and releasing pawls to the respective positions in which they are ready to perform their function of limiting the rotation of the said notched wheel, and means to disengage the said spacing and releasing pawls from the said notched wheel, substantially as set forth and described.

1. In a drawing board, in combination, a straight-edg a straight-edge controlling wire, a spacing device consisting of a drum around which the said controlling wire is coiled, a notched wheel rotating with the said drum, a movable arm rotatable about the axis of the said drum, means for fastening and adjusting the said arm, a spacing pawl and a releasing pawl, both of which are pivotally stoen to perform their function of limiting the rotation of the l0 said notched Wheel, and means to disengage the said spacing and releasing pawls from the said notched wheel, substantially as set forth and described.

HENRY L. BURBANK. JAMES W. MANSON. Witnesses T. W. KIMBER, CHARLES H. STAHL. 

